Question

can anyone explain this?

Answer 1

hi there!

Answer 2

hi :)

Answer 3

so you want understand what exactly in this question

Answer 4

the process of doing it, I wasn't taught this but it's extra credit so I'd like to know how to find the answer

Answer 5

sure :)
you do understand what the symbol tell us yes?

Answer 6

I don't :/

Answer 7

\[\sum _{i=1}^{100}\]
do you understand what this means

Answer 8

I searched it and it says it stand for the element of?

Answer 9

stands*

Answer 10

ok so that symbol is telling to sum from 1 to 100
but what are we summing here that is what we want to find yes

Answer 11

yes

Answer 12

it stands for summation from a starting point to an ending point
so no big deal really

Answer 13

okay

Answer 14

ok so what we are summing here is the natural number starting from 1 to 100
since we have \[\sum_{i=1}^{100}i\]

Answer 15

what do the i's stand for?

Answer 16

that i'm going to explain now :)

Answer 17

that i is telling us
for the index i=1
put the first term 1
for i=2 put 1+2
for i=3 put
1+2+3
and so tell 100

Answer 18

the index is the bottom i+
the i that is on the line is telling us what are we summing up
\[\sum_{i=1}^{100}i=1+2+3+4+5+6+....+100\]

Answer 19

you see how it goes
say you have this \[\sum_{k=0}^{8}4k\]
what you gonna do is
\[\sum _{k=0}^{8}4k=4(0)+4(1)+4(2)+4(3)+4(4)+4(5)+4(6)+4(7)+4(8)\]

Answer 20

ohh okay I see, is there like a way to do it or do i just have to add?

Answer 21

good question!

Answer 22

actually there a famous formula proved by gauss (a mathematician)
that helps you add up a large summation of natural numbers
feel free to check how this guy finds the formula

Answer 23

i will give you the formula and if you are interested see some video that show it came along

Answer 24

so the formula is :
\[1+2+3+4+...+n=\frac{n(n+1)}{2}\]
if we are summing n natural numbers

Answer 25

for n do I plug in 100 since it is the last # to be added?

Answer 26

here in your example we are summing from 1 to 100

Answer 27

yes exactly

Answer 28

wow okay thanks!!! (:

Answer 29

np dear :)

Answer 30

do check it really:)
it is interesting to know how thing are developed ^_-